Terradepth Achieves IHO Special Order Standard for Seabed Mapping Accuracy

25 September 2025

(Image credit: Terradepth)

Terradepth, a seabed information company, successfully completed an IHO S-44 Special Order survey with an autonomous underwater vehicle (AUV). This achievement meets one of the most stringent international standards for hydrographic accuracy. Using advanced AUV technology, Terradepth demonstrated that high-specification surveys no longer require costly, high-footprint operations.

“This milestone marks a tide-shifting moment for the hydrographic community, proving that Terradepth AUV-based surveys meet the most rigorous seabed mapping specifications,” said Joe Wolfel, Chief Executive Officer and Co-Founder of Terradepth. “It is a benchmark traditionally reserved for large, crewed survey vessels and towed sonar systems. With the team’s achievement, we hope the offshore community sees the opportunities inherent in high specification autonomous hydrography.”

The survey took place in approximately 80 meters of water, 60 miles offshore in the Gulf of America, a region affected by hurricanes and subsea infrastructure development. Despite the absence of local tide stations or buoys, European Remote Sensing (ERS) satellite radar was used to correct for tidal variations, demonstrating a fully autonomous and low-logistics survey approach.

The IHO S-44 Special Order standard relates to areas where underkeel clearance is critical. Therefore, 100% feature search and 100% bathymetric coverage are required, and the size of the features to be detected by this search is more demanding than lower IHO orders.

As part of Terradepth’s delivery model, survey results were processed and delivered through Absolute Ocean®, the company’s secure, cloud-native ocean data platform. This streamlined delivery enabled efficient execution and rapid access to results. It also empowers stakeholders to perform quality assurance, quality control, visualization, and decision-making from anywhere.

Terradepth’s autonomous approach dramatically reduces surface support requirements, cutting carbon emissions, operational costs, and personnel risk while maintaining industry-leading data quality.

The achievement of the IHO Special Order standard has broad implications across various industries. AUV-enabled surveys yield crucial insight into seabed characteristics, infrastructure integrity, and cable/foundation conditions across all depths. Further, Terradepth’s data and information quality satisfy National Marine Fisheries Service permitting exemptions and most BOEM requirements.

For government agencies and offshore energy operators, this successful IHO Special Order certification proves the readiness of Terradepth’s AUV-collected data and processed information for operational use.